1. Field of the Invention
The present invention relates to a substratum for cell culture capable of improving and enhancing the adhesion and proliferation activities of cells to the substrate and a method for incubating and isolating the cells by using the substrate.
2. Description of the Prior Art
Collagen exists in various organs such as blood vessels, skin, liver, pancreas, kidney, as main component of the connective tissue. Collagen also functions as a supporting substance for cell growth and plays an important role as the matrix for manifestation of the functions of tissues and organs. Atelocollagen which is prepared by pepsin treatment of acid-soluble collagen or insoluble collagen has been widely used as substrate for animal cell culture. Therefore, it is clear that collagen has a superior property as the matrix of cells in vitro.
Recently, studies on the artificial organs have been developed and studies on the artificial organs incorporated with cells peculiar to each organ, that is to say, studies on the hybrid organs have been actively conducted. For instance, the development of a hybrid organ for the liver in which hepatocytes are incorporated while maintaining cell metabolic activities. In this case, it is important to adhere the cells to the substrate without losing the cell activity same as that in in vivo. The choice of the kind of the substratum used is the point of success. As the substratum for liver cells, collagen extracted from the liver is reported to be superior. (M. Rjkind et al, Connective Tissue Biomatrix: Its Isolation for Longterm Culture of Normal Rat Hepatocytes. J. Cell Biol. 87, 255 (1980)).
Also so called methods of cell technology such as cell culture and cell isolation are occupying one of the important scientific technical fields in the advancement of life science. That is to say, effective cell culture and the isolation technique of cells are the most important technique in cell technology for the production of biologically active substances derived from cells. In the culture of animal cells, it is important to select the substratum with good adhesive property of cells in order to keep the original cell activity or in order to make the cells proliferate. Also it is usually necessary to add bovine fetus serum to the culture medium in order to maintain the cell activity or to proliferate cells. However, recently, owing to the difficulties of availability and expensiveness of bovine fetus serum, the establishment of a serum free cell culture method has been earnestly desired. And recently, fibronectin which is a kind of protein has been noticed as a cell attachment factor and the cell culture in the system of fibronectin instead of bovine fetus serum has been established.